Composite Intermediate Bulk Container (IBC), commonly known as tons packaging plastic barrels, comprises a liner and a frame. Composite Intermediate Bulk Container (IBC) can be used repeatedly. The cost can be significantly reduced when it is used to be filled, stored or transported. A discharging valve is installed at the bottom of the composite intermediate bulk containers (IBC) so as to facilitate to discharging residue from the container. However, during transportation, tamper-evident device needs to be installed on the valve to prevent materials stored from being stolen.
In current valve tamper-evident device for composite intermediate bulk container (IBC), a plurality of holes are usually provided on a screw cap, and corresponding holes are usually provided on the valve body or handle of the valve. Then, binding strips are used to pass through the holes on the screw cap and the holes on the valve body or handle, so as to lock the screw cap, which cannot be unscrewed. Disadvantageous of this tamper-evident device is that the valve is located in a narrow pit at the bottom of IBC, and installation and removal operation of the binding strips is very difficult and generally requires tools, thus cause inconvenience to the operator.
For example, Chinese Patent CN2640951Y discloses another tamper-evident device for valve, that is, an anti-theft plastic cover equipped with an anti-theft bar. The plastic cover includes the anti-theft bar and a screw cover. A protrusion is provided on the screw cover to be interlocked with a protrusion provided on the container mouth. Toothed sheets used to be snapped on the container mouth are densely arranged inside of the anti-theft bar. The anti-theft bar is connected to the screw cover through small plastic pieces evenly arranged along the periphery of the anti-theft bar. The small plastic pieces are located at the narrow gap between the upper screw cover and the lower anti-theft bar. Disadvantages of this tamper-evident device for valve are as follows. The anti-theft bar is inconvenient, inefficient and very difficult to be installed. In order to open the container, it needs a tool or greater effort to destroy the anti-theft strip. As connecting portion of the body of the cover and the anti-theft strip is more weak, the body of the cover is easily broken, which affect the use of the valve. Manufacturing requirements and cost for anti-theft cover is high. The anti-theft cover and the anti-theft bar are connected as a whole. When opened, the anti-theft bar is disengaged from the anti-theft cover, thus the anti-theft cover cannot be reused, resulting in waste. Further, since the anti-theft bar is easily lost after disengaged from the anti-theft cover, it brings troubles for clearing surrounding environment.
In other tamper-evident devices, such as flanges on the valve welded to PE bags, since the size of the welding head of the flanges are secured, an anti-theft buckle must be assembled after completing welding, which is more complicated and easy to omit.